diff --git a/apps/web/src/lazurio/threadTabs.test.ts b/apps/web/src/lazurio/threadTabs.test.ts
index a09cfcce330c..815246842a73 100644
--- a/apps/web/src/lazurio/threadTabs.test.ts
+++ b/apps/web/src/lazurio/threadTabs.test.ts
@@ -7,6 +7,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vite-plus/test"
 import { toastManager } from "../components/ui/toast";
 import {
   type RightPanelSurface,
+  selectActiveRightPanelSurface,
   selectThreadRightPanelState,
   type ThreadRightPanelState,
   useRightPanelStore,
@@ -21,6 +22,7 @@ import {
   newTabSurface,
   parseThreadTabsAnswer,
   placesOf,
+  receiveForeign,
   receiveSnapshot,
   reconcileThreadTabs,
   resetThreadTabs,
@@ -138,6 +140,25 @@ describe("the strip from the server's list", () => {
     });
   });
 
+  it("selects the first tab where nothing is selected, so the panel never opens on Nová karta beside them", () => {
+    expect(
+      reconcile({ isOpen: false, activeSurfaceId: null, surfaces: [] }, [id(1), id(2)]),
+    ).toEqual({ isOpen: false, activeSurfaceId: tab(1).id, surfaces: [tab(1), tab(2)] });
+    // A panel stored with tabs and no selection takes one even when the list brings nothing new.
+    const unselected = { isOpen: true, activeSurfaceId: null, surfaces: [tab(1)] };
+    expect(reconcile(unselected, [id(1)])).toEqual({ ...unselected, activeSurfaceId: tab(1).id });
+    // An empty strip stays as it is.
+    const empty = { isOpen: true, activeSurfaceId: null, surfaces: [] };
+    expect(reconcile(empty, [])).toBe(empty);
+  });
+
+  it("selects another Environment's tab the server announces where nothing is selected", () => {
+    setPanel({ isOpen: true, activeSurfaceId: null, surfaces: [] });
+    receiveSnapshot(threadA, snapshot([]));
+    receiveForeign(threadA, { tabId: "ab".repeat(16), view: foreign.view });
+    expect(panel()).toEqual({ isOpen: true, activeSurfaceId: foreign.id, surfaces: [foreign] });
+  });
+
   it("drops this Environment's unlisted tabs and keeps pending ones, Nová karta and other Environments' tabs", () => {
     const newTab = newTabSurface();
     const state = {
@@ -250,6 +271,22 @@ describe("reveals", () => {
     expect(panel()).toEqual({ isOpen: true, activeSurfaceId: tab(1).id, surfaces: [tab(1)] });
   });
 
+  it("leave the agent's tab of a thread that comes into view selected, for the panel the person opens", () => {
+    // The agent opened the page while the thread was out of view (or before a reload): its
+    // reveal is in the first snapshot, a baseline, so the panel does not open by itself...
+    syncOf(threadA).inlinePanel = true;
+    receiveSnapshot(
+      threadA,
+      snapshot([{ tabId: id(1), agent: true, revealRequest: { id: "epoch-1:1" } }]),
+    );
+    expect(panel()).toEqual({ isOpen: false, activeSurfaceId: tab(1).id, surfaces: [tab(1)] });
+    // ...and when the person opens it, it shows the agent's page, not Nová karta.
+    useRightPanelStore.getState().toggleVisibility(threadA);
+    expect(
+      selectActiveRightPanelSurface(useRightPanelStore.getState().byThreadKey, threadA),
+    ).toEqual(tab(1));
+  });
+
   it("give way to a choice the person made since the snapshot came", () => {
     syncOf(threadA).inlinePanel = true;
     setPanel({ isOpen: true, activeSurfaceId: files.id, surfaces: [files] });
diff --git a/apps/web/src/lazurio/threadTabs.ts b/apps/web/src/lazurio/threadTabs.ts
index 8db2d327a7fe..ba9710487bc5 100644
--- a/apps/web/src/lazurio/threadTabs.ts
+++ b/apps/web/src/lazurio/threadTabs.ts
@@ -154,7 +154,10 @@ export function parseForeignTab(value: unknown): ForeignTab | null {
  * `kept` (pending holds, tabs the device keeps itself) has. Every other Environment browser
  * surface goes, lazurio.7's included (its own tab and its new tabs at the view's bare origin).
  * Listed tabs without a surface are added at the end, in the list's order, without opening a
- * closed panel. An active surface that went falls back as upstream's reconciliation does.
+ * closed panel. Where nothing is selected, or the selected surface went, the first Environment
+ * browser tab is selected, as upstream's reconciliation does for its browser: the panel never
+ * opens on the empty Nová karta beside tabs of the strip whose frames it would not load (a thread
+ * that comes into view after its agent opened a page, whose first snapshot reveals nothing).
  */
 export function reconcileThreadTabs(
   current: ThreadRightPanelState,
@@ -181,20 +184,18 @@ export function reconcileThreadTabs(
       id: tabSurfaceId(tabId),
       kind: "environment-browser",
     }));
-  if (added.length === 0 && surfaces.length === current.surfaces.length) return current;
   const next = [...surfaces, ...added];
-  const activeStillExists = next.some((surface) => surface.id === current.activeSurfaceId);
-  return {
-    ...current,
-    surfaces: next,
-    activeSurfaceId: activeStillExists
-      ? current.activeSurfaceId
-      : current.activeSurfaceId === null
-        ? null
-        : (next.find((surface) => surface.kind === "environment-browser")?.id ??
-          next[0]?.id ??
-          null),
-  };
+  const activeSurfaceId = next.some((surface) => surface.id === current.activeSurfaceId)
+    ? current.activeSurfaceId
+    : (next.find((surface) => surface.kind === "environment-browser")?.id ?? next[0]?.id ?? null);
+  if (
+    added.length === 0 &&
+    surfaces.length === current.surfaces.length &&
+    activeSurfaceId === current.activeSurfaceId
+  ) {
+    return current;
+  }
+  return { ...current, surfaces: next, activeSurfaceId };
 }
 
 /** What the panel has seen of the server's reveal requests, per run of the server (`epoch`). */
@@ -428,7 +429,9 @@ const panelOf = (threadRef: ScopedThreadRef) =>
 const hasSurface = (threadRef: ScopedThreadRef, surfaceId: string) =>
   panelOf(threadRef).surfaces.some((surface) => surface.id === surfaceId);
 
-/** Adds a surface, in front with the panel open, or behind the surface in view. */
+/** Adds a surface, in front with the panel open, or behind the surface in view. Where nothing is
+ * selected it is the one selected, as in the strip after the server's list, and a closed panel
+ * stays closed. */
 function withSurface(
   current: ThreadRightPanelState,
   surface: EnvironmentBrowserSurface,
@@ -439,11 +442,7 @@ function withSurface(
     : [...current.surfaces, surface];
   return front
     ? { ...current, isOpen: true, surfaces, activeSurfaceId: surface.id }
-    : {
-        ...current,
-        surfaces,
-        activeSurfaceId: current.activeSurfaceId ?? (current.isOpen ? null : surface.id),
-      };
+    : { ...current, surfaces, activeSurfaceId: current.activeSurfaceId ?? surface.id };
 }
 
 /** Removes a surface the way upstream closes one: the neighbour comes to the front. */
diff --git a/docs/operations/lazurio-fork-release.md b/docs/operations/lazurio-fork-release.md
index f36fc8d93d0e..6ba73639231c 100644
--- a/docs/operations/lazurio-fork-release.md
+++ b/docs/operations/lazurio-fork-release.md
@@ -355,7 +355,11 @@ T3 žádný prohlížeč nemá, a tak overlay dělá tohle:
   servíruje, sleduje stránka seznam vlákna a každé zařízení srovná svůj pás s
   tímtéž seznamem. Nové záložky přidá na konec v pořadí souboru a neotevře jimi
   zavřený panel; kde už záložku ukazuje, zůstává volbou zařízení (záložky jde
-  přetahovat, i povrchy overlaye). Povrch je `environment-browser:<ID>` (id
+  přetahovat, i povrchy overlaye). Kde není vybraný žádný povrch, nebo vybraný
+  zmizel, vybere první záložku prohlížeče jako upstream srovnání svého
+  prohlížeče, takže se panel otevře na ní, a ne na prázdné Nové kartě vedle
+  záložek, jejichž rámy by nenačetl (vlákno přijde do zobrazení až po tom, co
+  agent stránku otevřel). Povrch je `environment-browser:<ID>` (id
   velkými písmeny) bez adresy; rám ukazuje `<origin pohledu>/t/<ID>` s originem
   ze snímku. Jen záložka jiného Environmentu má uloženou adresu (`view`). Čekající
   podržení srovnání nezahodí, pozůstatky lazurio.7 (vlastní záložka vlákna, nové